a number consists of digits 1 and 2.
the sum of its digits is 2018.
if the number is multiplied with 5,
the sum of the digits will be 10000.
find how many digits this number
has.
the curve y = f(x), when f(x) is a quadratic expression has
a maximum value point at (1,4). The curve touches the line
6x + y = 13. Find the value of x for which y = 8